This is a new application to acquire a digital high frequency cardiovascular ultrasound system to be used for cardiac imaging in small animals, mainly mice, and studies of vascular structure and function in humans. This system will be shared among a scientifically diverse group of PHS-supported investigators representing 7 departments at Washington University (Internal Medicine, Pediatrics, Pathology, Molecular Biology & Pharmacology, Cell Biology & Physiology, Biomedical Engineering, and Physics). Each member of the group has successfully used this system, which is available on a temporary basis as a loaner, and has demonstrated a significant need in the future. Accordingly, this requested shared instrument will have a major impact on the success of current and suture PHS-supported research activities of this user group. The proposed applications of the cardiovascular ultrasound system are focused on three major target research areas: i) characterization of mouse models of cardiomyopathy due to alterations in myocardiac hypertrophy in vivo using mouse models, and iii) application of high resolution ultrasound to vascular structure and functions in humans. In addition, several users will conduct basic ultrasonic research relevant to the physiology and material properties of the mouse models of cardiovascular disease developed by the user group. The requested instrumentation will be housed in dedicated space within the Small Animal Cardiovascular Physiology and Imaging Core Facility in the Center for Cardiovascular Research at Washington University School of Medicine. The system will be maintained and operated by a technical director and co-director within the Core facility. Validation studies are currently underway and plans have been made to establish an echocardiography database. This outstanding imaging tool will promote the success of the individual user's research program as well as facilitate multi- disciplinary efforts aimed at the characterization of the cardiovascular phenotype of mice generated through gene targeting and transgenic strategies. Acquisition of the requested cardiovascular ultrasound system is pivotal for the success of current and future PHS-funded cardiovascular research programs at Washington University.